This invention relates to the art of manufacturing containers from paperboard webs, and more particularly to a device for removing waste pieces from paperboard sheet material defining a web of indefinite length. Each removed waste piece often defines an opening in a container formed by the folding of blanks cut from the web. Typically, one or more cutter elements are mounted on the periphery of one of a first pair of rotating rolls, with the paperboard web passing through the nip of the rolls. The cutter element or elements on one of the rolls of this first pair partially cuts plugs from the web, and downstream of this cutting operation, pins or barbs mounted on one roll of a second pair of rolls engage and pierce the plugs to remove them from the web. After such plug removal, the web may be subsequently cut, provided with score lines and the like for the formation of containers.
The art is aware of apparatus for carrying out similar functions as may be seen for example in U.S. Pat. Nos. 2,677,994 issued to Schneider; 3,503,309 issued to Jones; 3,877,353 issued to Smith et al; and 4,295,842 issued to Bell.
While the pick or barb elements known in the prior art have performed more or less satisfactory, their reliability (always removing a plug) and particularly their tendency to break is less than desirable.